SL55 AMG, SL63 AMG, SL65 AMG (R230) 2002 - 2011 (2003 US for SL55 and 2004 for the SL65)

SL55/63/65/R230 AMG: loosing coolant

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Old Dec 21, 2018 | 02:55 PM
  #1  
mudjunkie's Avatar
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2003 SL55 AMG
loosing coolant

my first visit for this to my local MB specialty shop resulted in a "it seems ok, can't find anything" report. They did a coolant pressure test.
I've got these issues and wondered if someone might have an idea.

I've got 3 obvious symptoms
  1. thick foam at oil cap. engine oil is clear when observed on a dip stick, also when drained and the oil inspection plug rubber has clear oil on it.
  2. going through a 1/4 cup (or more) coolant per day of low mileage driving
  3. coolant system doesn't seem to be under much pressure. I'm able to open the reservoir cap immediately after driving with only a puff of pressure release.

and these non symptoms
  1. no engine noise on start up
  2. no over heating
  3. no smell of coolant outside or inside the car
thoughts? Thanks
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Old Dec 21, 2018 | 07:18 PM
  #2  
FxFormat's Avatar
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From: Northern VA
SL 600
Coolant doesn't evaporate so it's gotta be going somewhere. That foam at the oil cap is suspect that you might have a leaking head gasket and coolant is going in there. You can try to do a head gasket leak test with the chemical kit to see if you've got combustion gas inside your cooling system. If you can't see the leak, and it's still losing coolant then chances are it's the head gasket.
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Old Feb 29, 2024 | 11:45 AM
  #3  
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2003 SL55
I am also having this issue. The exact same one. Anyone else experienced this before?
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Old Mar 2, 2024 | 08:44 AM
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It’s more than likely one of a few things. The intercooler, or the front cover orings, and possibly but not extremely likely, the radiator trans cooler. The front cover orings dump the coolant into the oil pan, the head gaskets rarely fail.

The water pump can be removed to visually inspect the orings for swelling.
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Old Mar 2, 2024 | 10:16 AM
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From: DFW
SL63
Loosing: releasing, freeing, unrestrain, et al. setting free.
Losing: reducing numerically, reducing figuratively, at a comparative disadvantage, failing to retain, failing to contain.
I am defining these words off the top of my head. An official dictionary might define them better or more accurately.
It just irks me, and is a pet peeve of mine.
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Old Mar 3, 2024 | 10:12 AM
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Unfortunately with your posted description of the two words, either word could be used. The coolant is definitely unrestrained and being set free as well as not being contained.
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Old Mar 3, 2024 | 11:07 AM
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From: DFW
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Originally Posted by cdk4219
Unfortunately with your posted description of the two words, either word could be used. The coolant is definitely unrestrained and being set free as well as not being contained.
Although the 2 words have similar aspects, they cannot be used interchangeably.
Its improper and most likely a spelling error, or a misunderstanding of the definition.
From study right UK…
“Losing is the present participle of the verb 'lose', which signifies a loss, or being deprived of something. Loosing is the present participle of the verb 'loose', meaning to unfasten, let go, or release.”
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